The Real Father
by HalfbloodArcher
Summary: Karasuma has just found out some shocking news in an email. Korosensei is a dad! A story based off a little fan theory some of my friends have, in which Korosensei is the father of a person we all know pretty well. Oh, and probably some minor Karma x Nagisa. Also posted on Wattpad.
1. Chapter 1

"I have a son?" That's how it started.

Well no, that's not quite right. It all started with an email Karasuma received from the higher up's.

"What's this?" Karasuma muttered to himself, while scrolling through his emails.

The email was titled, Read Immediately!, sent by the higher up's. Karasuma sighed and began to read the email. As he read it, his face became less and less calm compared to the typical Karasuma we all know. When he finished, he slammed the laptop close and contemplated what he just read.

 _Korosensei has a son?_

The email, that had Karasuma so flustered, had said that the government had discovered that Korosensei had a son. A son that not even Korosensi knew about. Apparently, the son was a result of a one night stand Korosensei had over 14 years ago. The government had not yet discovered who the son was, but they were working around the clock in order to figure it out. They had figured that if Korosensei knew he had a son, he would not destroy the earth, in fear for his own son.

How the government had figured all this out? Karasuma didn't even want to know.

The email also said that they would contact Karasuma when they had figured it out.

Now only one question remained.

 _How do I tell the octopus about this?_

After sitting down and considering his options for a while, Karasuma decided it was better to wait to find out who the son was, then tell Korosensei about this whole thing.

For the next few weeks, life in E-class continued normally. The kids continued to try to assassinate Korosensei, Korosensei was as cocky as always, everything was normal.

All that changed on a faithful Friday when Karasuma received a new email.

 _So I see its finally here._ Karasuma took a deep breath _. It's okay, I've been waiting for this. I just have to click on the email._

What he read, not even he was prepared for.

 _Nagisa Shiota_

 _That_ was the name contained in the email.

 _Okay don't panic, just claim down_. _I just have to explain the situation to them. I mean, I'm sure they'll be shocked, but I have to tell them._

 _But who do I tell first. The octopus or Nagisa._

After contemplating it for a while, Karasuma decided it would be best for him to tell Korosensei first, then have Korosensei decide what to do with the information.

Karasuma decided to wait until the end of the day to tell Korosensei.

"I need to talk to you about something, it's important."

Afterward, Karasuma and Korosensei walked into Karasuma office.

"Please, sit down," Karasuma said.

Karasuma then went on his laptop and pulled up the first email.

"Read this, you'll understand."

Korosensei looked up at Karasuma, with confusion written on his face, but he complied non-the-less.

The room was silent as Korosensei read the first email. After a while, Korosensei looked up to Karasuma.

"I have a son?" Korosensei plaused, waiting for Karasuma to reply. Karasuma nodded his head.

"Who is it," asked Korosensi, "I'm assuming you know since I doubt you would tell me this information unless you knew."

Karasuma nodded his head again. He then took the laptop and pulled up the second email.

Korosensei took a deep breath and preceded to read the second email.


	2. Chapter 2

**AN**

 **First of all, I would like to thank everyone who has review, favorited or followed this story. This is my first story so I was really scared of its react. Thank you so much for all your kind words and support!**

 **The next part should be up sometime tomorrow. I am currently in the process of writing the next chapter so it will be done soon.**

 **I am also going to try to write longer chapters. Thank you all again ~HalfbloodArcher**

* * *

"O-oh" Korosensei stuttered, looking up from the email. "Nagisa's my son?"

"yes," Karasuma repied, then he paused, he looked at Korosensei and replied," I thought in this situation it would be best to let you decide what to do next." "Do you want to tell Nagisa, and if so how do you want to tell him?"

"Yes," Korosensei spoke," He deserves to know." He paused again. "Give me the weekend to think about it and I'll tell him on Monday."

"Okay, take as much time as you need to think this through."

* * *

Monday came quicker than Korosensei expected.

 _Okay, I've spent the whole weekend thinking about this, I just need to tell him._

Korosensei spots Nagisa walking with Karma and Kayano.

 _Maybe I should wait until the end of the day to tell him._

The day went on as normal, except for Korosensei less than normal behavior _._ Lets just say the students were a little more the suspicious at his behavior. They questioned him on why he was acting so weird, but he denied it. Eventually the students gave up and dropped the subject.

The end of the day came far to soon for Korosensei.

Korosensei looked at the clock.

 _Its time_.

As the last bell of the day rang, and E-class started to leave, Korosensei called out to Nagisa.

"Nagisa, please stay for a few minutes."

Nagisa, who was talking to Karma while walking to the door, stopped.

"Go ahead without me," Nagisa said quietly to Karma.

"I'll meet you outside," Karma responded to Nagisa.

Nagisa walked toward Korosensei.

"What do you want to talk to me about sir?" Nagisa questioned.

"Nagisa, I have something very important to talk to you about, but I'm not sure how you'll react."

"Please, just tell me."

"Okay," Korosansei paused to take a deep breath, "the government has found out something about you. Your father is not your real father."

Nagisa's eye's grew wide with shock.

"Y-you mean I'm adopted?"

"No," Korosensei took a second to collect his thoughts," Your mother had an affair before you were born, you are your mothers child, but you have a different father."

Nagisa stared at Korosensei. He was frozen, then he sat down quietly and started shaking. The room was silent for a few minutes while Nagisa processed this information.

Finally, Nagisa spoke.

"Do they know who my real father is?"

"Yes," Korosensei replied. Nagisa paused again.

"Who is it?"

Korosensei took another minute and simply looked at Nagisa. Finally, Korosensei replied.

"Me."


	3. Chapter 3

**An**

 **Thank you so much to everyone reading this story! I rally appreciate all the support! XD**

 **WARING: Mild yaoi in chapter.**

* * *

To say Nagisa was shocked was an understatement. On the outside, he seemed fine, but on the inside he was freaking out. He wanted to believe that Korosensei was lying, that this was all just some sort of cruel joke, but by the look on Korosensei face, Nagisa new he wasn't joking.

 _Father! He's my father? How does he expect me to react to that?_

While Nagisa was having an internal breakdown, Korosensei was also terrified.

 _I told him, I really told him. Why is he so quiet? Please just same something, anything! The silence is killing me._

After a few more minutes of awkward silence and stares, Nagisa spoke.

"I-I really don't know what to think, please just give me some time to think this over." And with that Nagisa turned around and walked/ran out of the class room to the outside.

When Nagisa ran outside, he ran straight into something, or someone.

"N-nagisa, what's going on, what wrong?" Karma stuttered out.

Nagisa couldn't respond, he simply rapped his arms around Karma and clung on.

Karma wrapped his arms around Nagisa and tried to clam him down.

"Nagisa, it's alright. Please clam down. Tell me what wrong."

Finally Nagisa found his voice.

"I don't want to talk about it here, can we go somewhere else?"

"Sure."

Karma led Nagisa away from the school. They walked in silence, just staring at the road introns of them. After a while, they finally arrived at a house.

"Karma, what are we doing here?"

"I thought I might be easier to talk at my house." Karma responded while opening the door to his house.

"Please, come in."

The boys walked inside Karma's house.

Nagisa looked around, he was wondering why there was no other voices in the house. Karma caught Nagisa's confused look an answered him.

"My parents are on business over sea's, so no one's home."

"Oh," Nagisa responded quietly.

Karma then led Nagisa to his couch, when they both sat down, Karma asked Nagisa again.

"Do you want to tell me why you were crying now?" Karma questioned.

Nagisa thought over his options.

 _Do I really want to tell Karma? He is my best friend, but I don't know if I should or not. He looks really worried though. Maybe I should tell him. He might even have advice in how to handle this situation._

After thinking about it for a while, Nagisa decided it was best to tell Karma.

"Korosensei told me something and I don't know what to do about it."

"What did he tell you?" Karma questioned.

"He's my father."

Karma's face was in pure shock.

"W-what, but how is that even possible?"

"Apparently my mom and him had an affair before I was born."

Nagisa's eyes started to water again. Kamra quickly reached over and pulled Nagisa into a hug.

"Hey, its going to be alright," Karma started to say,"Just think about it, if Korosensei your dad, that must mean you've inherited some of his skill right? That's awesome!"

"Also is Korosensei's your dad, I bet we could get away with a lot more in class, just think of all the pranks we could pull!"

 _Karma is wearing that smirk of his again, though this time I can tell he's just doing it to cheer me up. That's just like Karma, always trying to cheer people up by making them laugh. Maybe I should play along._

 _"_ Karma,one I doubt Korosensei would give us special treatment, and second we? I think you mean me." Nagisa said with a little smile on his face.

"Just you, are you kidding? No way, I'm using best friend privileges."

"Karma, that's devious."

"What else would you expect from me?" Karma was full on smirking now.

"Karma?"

"Yeah?"

"Thanks for cheering my up." Nagisa said sweetly.

"Well I can't have my best friend sulking, now can I?"

 _Is Karma actually being genuine_?

"Who else do am I going to tease?"

 _That sounds more like Karma._

Nagisa stood up and looked at the clock _._

 _"_ Oh crap, it's that late already, sorry Karma I got to go. See you Tomorrow _."_

 _"_ Bye Nagisa _."_

 _"_ Bye Karma," Nagisa paused for a moment. With a sweet simile, he turned back toward Karma, "Thank you."

With that, Nagisa left Karma's house and started to head home. About half way to his house a thought crossed Nagisa mind.

 _Oh crap, how am I going to face my mother?_


	4. Chapter 4

**AN: Hey Guys, thank** **you so much for all the reviews and follows! If anyone has any ideas on how to improve my writing or this story, please let me know.**

 **I Also realized I've been forgetting to put a disclaimer so, DISCLAIMER: I do not own Assassination CLassroom.**

 **I Hope you guys enjoy chapter 4. :) ~HaldbloodArcher**

* * *

 _My-my mother. How am I ever going to face her now? I can't tell her I know, she would just question how I found out. Even if I do tell her, she might just get angry with me and go into her control freak mode or she might just brush it off and not answer me. Either way, She won't listen to a thing I have to say on the subject._

Nagisa started pacing around in circles, murmuring to himself, trying to come up with a plan. Strangers walking by must have thought he was some kind of lunatic and stared clear of him.

"Honey, stay away from the strange child." One woman said while taking her child's hand and pull her away from the crazy man.

"What is wrong with kids these days." A man muttered under his breath.

Nagisa didn't seem to notice any of these comments though, he was far to deep in his thoughts.

After a few more minutes of thinking, Nagisa finally snapped out of said state.

 _Okay, I just need to play it cool and not mention anything to her. It's probably better this way anyway. If I questioned her on it, she would just ask to many questions that I wouldn't be able to answer without giving up The E-class secret._

After Nagisa had made up his mind, he started to walk down the road again. Nagisa walked along the road in silence, in a few more minutes, he reached his house.

He paused as he reached the front door.

 _Just open the door and act normal._

Nagisa gently pushed the door open.

"Welcome home from school Nagisa."

Nagisa, with a giant simile planted on his face, responded to his mother, " Hello mother, how are you today."

"Nagisa, is anything wrong?"

 _I really need to work on my deceptive skills..._

"No mom, I had a great day," Nagisa started to back up and walk slowly towards the stairs,"we'll, if you don't need me, I'll, be up stairs in my room."

"Nagisa..." His mother trailed off, giving him a skeptical look.

"Mom, I promise, I'm fine."

"Okay, if your sure," Nagisa mom sounded reluctant to let him, but agreed non-the-less.

Nagisa walked up the stairs quietly, when he reach the top and was invisible to his mother's view, he quickly ran into his room and shut the door behind him.

 _That was harder then I thought, how am I ever going to keep this up? Mom definitely suspects something too. Nagisa sighed. Whatever, it's been a long day and I'm so tired. I'll just take a little nap before dinner and clam my thoughts. My head feels like it's pounding._

Nagisa crawled into bed and set his alarm to a couple minutes before dinner time. With that, he laid down and fell asleep soundly.

* * *

The Next Day

When Nagisa woke up the next morning, the sun was shinning, the birds were singing, everything was clam and peaceful. Nagisa was calm and felt at peace.

At that moment, he remembered. He looked out the window and one thought came to mind.

 _Great, the universe just loves to tease me, doesn't it._

With that thought, Nagisa got up and started to get ready for school. He grabbed his uniform form his closet and got changed sluggishly. After he decided he looked presentable enough for school, he went down stairs to get breakfast ready.

While he was preparing breakfast, his mother came down.

"How are you feeling today Nagisa?" Said woman question while sitting down at the table.

"Much better today mom," Nagisa lied through his teeth," I think I just needed a good nights sleep."

"Well that's good I guess."

Nagisa let out a sigh of relief.

"So what are you making?" His mom questioned.

"Eggs and toast."

After that the conversation stopped, and Nagisa finished the food in silence. When he finished, he brought the food to the table and they ate in silence.

Nagisa mother glanced at her watch.

"Nagisa, you better get going or else you'll be late for school."

At that, Nagisa cleaned his plate, grabbed his bag, and went out the door.

"See you after school mom!" Nagisa called out as he was leaving.

"Have a good day." His mother responded.

With that, Nagisa closed the door behind him, and started walking to school.


	5. Flashback Time

**Thank you to everyone who has reviewed, followed, or favorite this. Sorry this chapter took so long to come out.**

 **Disclaimer: I do not own assassination classroom**

* * *

 ** _~~~~~Flashback~~~~~_**

It was a cool , October night. The wind was blowing and the air had a bitter feel to it. This story starts at a bar, with woman, drunk and sulking in her sorrows, and man, drunk with a look certain look in his eyes, the look of regret, drinking away their problems. The women had short, dark blue hair. The man was tall, and had radiant black hair. His smile was kind, making him come off as totally innocent.

The woman's problem; she had just gotten into a fight with her new husband and she was their contemplating their fight.

The man's problem; he had just finished a particularly messy assassination job and so he sat there, trying to forget everything that had transpired.

"Penny for your thoughts," the man said turning to look at the woman next to him, trying to make conversation.

"It's nothing, just my stupid husband," the woman paused and turned to the man,"what about you."

"Just a hard day on the job," the man lied through his teeth. He couldn't very we'll tell this woman the real reason why he was upset, then he'd have to kill her.

"Oh, I'm sorry about that."

"It's fine, everyone has a bad day once in a while."

Silence swapped the bar after that, the only sounds to be heard were the music playing in the background and the murmurs of the others in the bar.

"Can I for you name?" The man asked.

"Hiromi Shiota," The woman replied, "and yours?"

"Hajime Gima," The man said the first name that came to mind, he could never put this poor lady in danger by giving her his real name, even if he was drunk, he's not that stupid.

"Well Hajime, its very nice to meet you."

"Same to you miss"

Everything spiraled after that.

The man ended up bring the woman back to the hotel he was staying at, lets just leave the rest up to your imagination.

* * *

 _ **Still Flashback, but one month later**_

Hiromi stood up and flushed the toilet. She had been feeling very sick lately. Throwing up, but strangely only in the mornings. Hiromi knew what this met, but she was to scared to face the truth. She had been putting this off for a while, but she finally decided that it was time.

"Sweetheart!" Hiromi called, " Can you take me to the hospital?"

Hiromi and her husband had made up from their fight the day after her one night stand, in case you were wondering.

The ride to the hospital was quiet, Hiromi was dreading the outcome.

After getting checked in and waiting in the waiting room for a few hours, a doctor finally came to get her. The doctor led her and her husband to a room.

"So what seems to be the problem miss?"

"I think I'm pregnant." There was no use in beating around the bush.

"Ah," Was all the doctor replied, he scribbled something down onto his clipboard.

After a few minutes, the doctor stood up, "Please, come with me ma'am. "

Hiromi followed the man to a secluded room. There the man did some test to determine if Hiromi was in fact pregnant or not.

"Well that's the last of the tests, please, go wait with your husband until, we know the results."

The woman nodded her head and headed back to her husband.

After a few minutes of waiting, which felt like torcher, the doctor finally came back in.

"Well miss, Congratulations, you are indeed pregnant, one month along it seems."

Hiromi felt like breaking down after that. Even if her husband wasn't smart enough to put it together, she was. She knew, her one night stand was going to be the true father of her child. A stranger would be the father of her child.

She couldn't cry now though, no, the tears would come later. Right now she had to be cheerful, act as though nothing was wrong, act as though her husband was the father of her unborn child.

In that moment she decided, no one would ever find out about this. The world would just continue to think her husband was the father, not some stranger. She would not have her life and her reputation ruined because of this, because of her one mistake. She would make sure no one would ever find out.

"Honey this is great!" Her husband said while smiling at her.

Hiromi took a deep breath and relaxed for a second, then she planned a big smile on her face. A smile that would fool anyone, masking her emotions completely.

"I'm so happy, were going to be parents."

* * *

 _ **Eight Months Later**_

"Congratulations Mrs. Shiota, you've given birth to a beautiful baby boy."


	6. Chapter 6

**AN: So, um, its been 2 months huh? I am so sorry. On the plus side though inspiration struck me and I finally know how I want this story to end. :)**

* * *

The walk to school was calm and peaceful, the sky was a bright blue and the grass was a sparkling green. Nagisa almost laughed at the irony of it all, here he was, close to a mental break down, and the weather just seemed to be teasing him. With that thought, Nagisa reached the classroom and when inside. Most of the students sat at their seats, talking with one another. Nagisa hastily made his way to his seat and sat down, trying not to call attention to himself. Unfortunately, things did not go as Nagisa planned. As he sat down, Kayano turned to him.

"Hey Nagisa, how are you today?" Kayano asked him with a smile on her face.

Nagisa put a smile on his face and responded, "I'm doing fine, how about you Kayano?"

Kayano had a questioning look on her face, "Are you sure your okay Nagisa?"

"Yes, I'm fine, don't worry." Nagisa replied.

"Okay then, if your sure," Kayano then shrugged her shoulders, then turned back around.

Nagisa let out a sigh of relief, _crisis averted for now, I don't want anyone else to find out, at least not yet._

A few more minutes of quiet chatter filled the room, then a blasted of wind came in, and standing there was Koro-sensei.

"Good Morning class, I will now start morning roll call." With that the day begun.

* * *

Lucky, or unlucky for Nagisa, the day seemed to go by pretty fast. Then finally, the end of the day came.

As the last bell rang out and the students scurried out of class, Nagisa approached Koro-sensei.

"Hello sir," Nagisa started to say, "Can I talk to you for a moment?" Nagisa asked.

"Of course, Nagisa." Koro-sensei replied.

Silence filled the air for a few minutes, Nagisa stared down at the ground, his eyes looked down at the floor, before finally he spoke, "Koro-sensei, I've been thinking about this a lot and I think I want to give this a chance, I mean that is, if you want to," Nagisa paused for a second and look up at Koro-sensei, "If you want to try to develop a father/son relationship, I wouldn't mind."

Koro-sensei stared at Nagisa in shock, in all of the possible outcomes he thought of, this was not one of them. Well, it was, but one he disregarded as something that could never happened. He refused to hope that Nagisa would ever want that kind of relationship with him, but he was wrong, so wrong. Here Nagisa was standing in front of him, asking him if he wanted at act like Nagisa father.

After Koro-sensei got out of his initially shock, he quickly answered Nagisa with a frantic voice, "Y-yes I would like to try that!" Koro-sensei stuttered out.

A smile grew on Nagisa face, "Okay than si-dad."

Being called dad for the first time, well Koro-sensei smile might have just grown bigger.

"There is one more thing though, do you think we can just keep this between us, Karasuma, and Karma. Sorry, I just don't think I'm ready for anyone else to know yet." Nagisa told Koro-sensei.

"That's fine with me," Koro-sensei replied.

* * *

After that, nothing much changed in class 3E, besides Nagisa and Koro-sensei hanging out more after school. Yes life continued on normal, well as normal as life can be in a classroom made for assassination.

That is, until a certain second God of Death showed up.

 **AN: Hey guys chapters should be coming out faster from now on, I finally have an idea on what direction I want to take this story in. See you next time**

 **~HalfbloodArcher**


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